TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by rscasny

rscasny — Wed, 22 Feb 2017 16:20:15 GMT

The start time for this webinar has been advanced one hour to accommodate the summer time change in Europe.

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by dandeen

dandeen — Thu, 16 Mar 2017 22:14:04 GMT

Is this the same webinar I saw a year and a half ago?

https://training.ti.com/ADCwebinar

What are the new things I can look forward to?

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by alicanmadan

alicanmadan — Wed, 22 Mar 2017 09:19:08 GMT

I am new in Webex. So is there any meeting number for webinar? I could not find any information about it. Thanks

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by jadew

jadew — Wed, 22 Mar 2017 14:57:54 GMT

Can't join, Chrome gets redirected back to a page with a continue button and with Firefox it says I need a Firefox version bigger than 51, even though I have version 52.

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by rscasny

rscasny — Wed, 22 Mar 2017 15:48:16 GMT

To download the webinar slides please click here and log into your myTI account or create a new one.

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by DAB

DAB — Sat, 01 Apr 2017 19:40:12 GMT

Very informative webinar.

DAB

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by rscasny

rscasny — Mon, 03 Apr 2017 21:28:53 GMT

Make sure you check out the webinar recording if you missed the webinar live.

re: TI SAR ADCs vs. Delta-Sigma ADCs: Different Architectures for Different Applications by rscasny

rscasny — Tue, 04 Apr 2017 16:46:42 GMT

Answers to questions asked during the live webinar:

I want to ask the limitations of delta sigma modulator. I am using AMC1304M25 and latency time-resolution trade off makes my control bandwidth small. Is it possible to measure up to 200 kHz with a great precision? Can Delta Sigma Modulators be used widely in high power density power supplies?

You can absolutely measure a 200 kHz signal with the AMC1304M25. The caveat here is the higher the bandwidth your signal is, the less precision you are going to have. The decimation ratio (Fs/Fd) of the modulator dictates how much noise will be able to be shaped out at higher frequencies when you do your digital filtering. Delta-Sigma Modulators also have no problems being used with high power density power supplies.

Should the front end match for BW?

Yes this is the case. When designing systems with SAR’s or Delta-Sigma’s, you would want to build your system and analog front end for the bandwidth of interest. As an example, you wouldn’t want to use a front end designed for a 5k Hz signal when you are attempting to measure a 45 kHz signal.

How does averaging several samples from an oversampling SAR affect its performance?

With the ‘snapshot’ way that SARs read signals, averaging several samples from a SAR would help you make sure that you have measured a steady signal or if your signal has deviated from the first sample.

Does the noise of the signal also spread out to larger BW and then filtered out by digital filter?

Yes, this is one of the main advantages of the Delta-Sigma ADC. The noise gets pushed out or ‘shaped’ and then the digital filter (usually a FIR filter) attenuates the noise at higher frequencies.

I have a TIA front end, and I will only capture data after it has settled. Do I need Anti-aliasing filter in this case? (for the Delta-Sigma)

With the way the internals of the Delta-Sigma modulator work, anti-aliasing is usually required for most AC signals. Delta-Sigma ADCs have to settle to acquire a signal anyways.

How do I figure out the RC for the anti-aliasing filter?

The RC constant needs to be chosen such that the cutoff frequency of your filter does not attenuate your signal of interest. Delta-Sigma ADCs usually only need a 1^st order anti-aliasing filter though. This is a great advantage to using Delta-Sigma’s.